Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Nitronic 60 Marine Fasteners - Anti-Galling Salt-Spray Hardware
Nitronic 60 marine fasteners (UNS S21800) are the anti-galling specification for shipboard, dockyard, and offshore-platform bolting where 304 / 316L hardware retires early from the cold-welding adhesion failure mode under repeated salt-spray exposure and disassembly cycles. The high-Mn-Si-N chemistry provides anti-galling without the cost of nickel-superalloy alternatives, while retaining adequate chloride-pitting resistance for general marine-atmospheric service.
TorqBolt stocks Nitronic 60 (UNS S21800) at our Mumbai head office and Rajkot production plant. Each consignment ships with EN 10204 3.1 mill test certification by default and 3.2 dual-witnessed inspection (Lloyds, TUV, DNV, BV) on request. Contact info@torqbolt.com or +91-22-66157017 for sized stock and lead time.
Service Envelope for Marine Fasteners
Marine hardware sees salt-spray cycling, dynamic loading from wave action, and repeated disassembly during maintenance. 304 / 316L bolts gall during disassembly, requiring destructive removal and replacement. Nitronic 60 anti-galling chemistry eliminates this failure mode. For higher chloride-pitting resistance specify duplex 2205 or Inconel 625 at higher cost; for anti-galling priority in marine atmospheric service Nitronic 60 is the engineering compromise.
- Deck hardware bolting, davit hinge pins, davit base bolts.
- Propeller-shaft coupling fasteners, propeller-flange studs.
- Sea chest cover bolting, sea-water inlet flange studs.
- Dockyard crane bolting, crane hinge pins.
- Helideck stanchion bolting, helideck net-attachment hardware.
- Salt-spray atmospheric corrosion: Nitronic 60 PREN ~18 is comparable to 304 (PREN ~19). For chloride-pitting priority specify duplex 2205 (PREN ~35) instead. See Nitronic 60 vs duplex 2205.
Target Components in Marine Fasteners
- Hex bolts, stud bolts, heavy hex nuts per ASTM A193 B8R / A194 8R.
- Anchor bolts for offshore platform foundations.
- Helicoil thread inserts in aluminum deck hardware.
- Dowel pins for repeated-disassembly hinged assemblies.
- Threaded rod for shipboard pipe-support brackets.
Chemistry — UNS S21800
Cr 16-18 / Mn 7-9 / Ni 8-9 / Si 3.5-4.5 / N 0.08-0.18 / C ≤0.10. See full element ranges with single and aggregate limits →
Mechanical Properties
Yield 55 ksi (380 MPa) min, tensile 95 ksi (655 MPa) min, elongation 35% min (annealed). Hardness Rockwell B95-95 typical. See full mechanical specification with bar / forging / wire conditions →
Galling Resistance
Nitronic 60 threshold stress 50,000 psi+ per ASTM G98 vs 304/316L at 4,000-6,000 psi — 5 to 10× better galling resistance. See full ASTM G98 data and galling failure mechanism →
Heat Treatment
Solution anneal only at 1900-1950°F followed by water quench. No precipitation hardening response. See full heat treatment specification →
Welding
Matching filler ER218 per AMS 5847. GTAW, GMAW, and SMAW all qualified. No PWHT required for typical thicknesses. See full welding procedure →
Material Selection
Nitronic 60 wins for anti-galling at high temperature where 304/316L gall. Stellite is harder but brittle. vs 316L · vs Nitronic 50 · austenitic context →
Nitronic 60 Applications by Industry
- Marine and offshore, anti-galling bolting and deck hardware.
- Oil and gas, subsea wellhead, NACE MR0175 sour service, christmas-tree fasteners.
- Nuclear, valve trim, pump shafts, reactor coolant bolting.
- Food processing, FDA-acceptable austenitic, sanitary fittings, mixer paddles.
- Cryogenic, LNG hardware, austenitic stability to -196 C.
- Pump and rotating equipment, shafts and bushings under sliding seal contact.
- Valve stems, gate / globe valve stems under pressure cycling.
- Anti-galling general applications, cross-industry summary.
Related Nitronic 60 Forms and Fasteners
- Bar: round bar, hex bar, square bar, flat bar.
- Plate, sheet, forgings: plate, sheet, forgings.
- Wire and tubing: wire, spring wire, tubing, seamless pipe.
- Bolts: hex bolts, stud bolts, anchor bolts, socket head cap screws.
- Nuts: hex nuts, heavy hex nuts, lock nuts, jam nuts.
- Pins and inserts: dowel pins, clevis pins, bushings, Helicoil thread inserts.
- Catalog: full Nitronic 60 fastener portfolio, anti-galling fasteners.
Request a Quote
For Nitronic 60 hardware specified for marine fasteners, Contact the TorqBolt QA-QC team at info@torqbolt.com or +91-22-66157017. We respond within 24 hours with sized stock availability, lead time, and EN 10204 3.1 / 3.2 MTC documentation samples.
Frequently Asked Questions
Why Nitronic 60 for marine fasteners?
The anti-galling chemistry eliminates the dominant failure mode of 304 / 316L hardware in marine fasteners. Specifically the threshold galling stress per ASTM G98 is 5 to 10 times higher self-mated.
What forms are typically specified?
Fasteners (hex bolts, stud bolts, hex nuts), shafts, bushings, valve trim, sliding-contact components. See full fastener portfolio for the catalog overview.
What certification is required for marine fasteners?
Typically EN 10204 3.1 mill test certificate as standard, with 3.2 dual-witnessed inspection (Lloyds, TUV, DNV, BV) for safety-critical or regulatory-monitored components. NACE MR0175 compliance available where sour-service exposure is part of the envelope.
Alternative materials for marine fasteners?
Duplex 2205 (better chloride resistance, moderate galling), Inconel 625 (high-temperature corrosion at much higher cost), Stellite 6 (extreme galling at 15 to 25 times the cost). Nitronic 60 is the stainless-price-point anti-galling specification.
Satisfaction Survey
